Stretchable coated fabric and process for producing same

ABSTRACT

A stretchable coated fabric is treated for water repellency with a fluorinated water repellent that comprises a copolymer containing a perfluoroalkyl group with six or less carbon atoms (C6 fluorinated water repellent). The use of no C8 fluorinated water repellents that contain perfluorooctanoic acid, perfluorooctane sulfonate, and the like makes the fabric exerts no influence on the environment. And the fluorinated water repellent has a toluene repellency of 100 seconds or longer; a synthetic resin solution applied to at least one side of the stretchable fiber fabric has a thixotropic index at 23° C. in a range from 1.4 to 2.0; and the synthetic resin has a 100% modulus of 5 kgf/cm 2  or greater. This prevents the synthetic resin from leaking to the back side and allows formation of a resin coating film that has good film forming properties.

TECHNICAL FIELD

The present disclosure relates to a stretchable coated fabric and a process for producing the same.

BACKGROUND ART

A need exists for a process for imparting water-oil-repellency to a surface of a garment that is a textile product. In particular, a process for using a C8 fluorinated water repellent to treat the surface has been used. As used herein, the term “C8 fluorinated water repellent” refers to a fluorinated water repellent that containing an emulsion of a copolymer comprises a perfluoroalkyl group with eight or more carbon atoms dispersed in a medium. However, the EPA (US Environmental Protection Agency) has discovered that the C8 fluorinated water repellents contain perfluorooctanoic acid, perfluorooctane sulfonate, and the like. These compounds degrade in the environment and in organisms. As their degradation products accumulate in the environment and in organisms, the compounds place a heavy burden on the environment. Thus, there is a need for a fluorinated water repellent that does not contain these compounds.

Then, a replacement to a C6 fluorinated water repellent is pushed forward rapidly. As used herein, the term “C6 fluorinated water repellent” refers to a fluorinated water repellent that comprises a copolymer comprises a perfluoroalkyl group with six or less carbon atoms. For example, Patent Literature 1 discloses a water-oil-repellent fabric using a C6 fluorinated water repellent and a process for producing the same. Moreover, in order to obtain a moisture permeable, waterproof, and windproof fabric, a synthetic resin solution that contains an organic solvent has been applied, for example by a dry process, to a fabric given a water-oil-repellency using a C6 fluorinated water repellent.

CITATION LIST Patent Literature

-   Patent Literature 1: Unexamined Japanese Patent Application Kokai     Publication No. 2007-270374

SUMMARY OF INVENTION Technical Problem

However, the C6 fluorinated water repellent has a relatively lower water-oil-repellency, compared with the conventional C8 fluorinated water repellent. If the C6 fluorinated water repellent is used to treat a fiber fabric only for water-oil-repellency, the fabric obtains, as initial performance, similar water-oil-repellency to a fabric using the C8 fluorinated water repellent. However, when the fiber fabric is subsequently coated with a synthetic resin solution, the synthetic resin solution penetrates the fiber fabric. It is presumed that this phenomenon occurs because a fabric treated with a C6 fluorinated water repellent has a lower dynamic oil-repellency offered by coating, compared with a fabric treated with a C8 fluorinated water repellent. Consequently, it is difficult to form a continuous resin film on a surface of the fiber fabric, which causes the problem that the necessary performance (hydraulic resistance, moisture permeability, wind proof property, and the like) is not provided.

The present disclosure has been developed in view of these problems, and directed to provide a stretchable coated fabric that exerts no influence on the environment and that is highly moisture permeable, waterproof, and windproof and a process for producing the same.

Solution to Problem

In order to achieve the objective described above, a stretchable coated fabric according to a first aspect of the present disclosure is

-   -   a stretchable coated fabric produced by treating a stretchable         fiber fabric for water repellency with a fluorinated water         repellent that comprises a copolymer comprises a perfluoroalkyl         group with six or less carbon atoms and applying a synthetic         resin solution to at least one side of the stretchable fiber         fabric to form a resin coating film that comprises a synthetic         resin,     -   wherein the stretchable fiber fabric treated for water         repellency with the fluorinated water repellent has a toluene         repellency of 100 seconds or longer, and the synthetic resin         solution has a thixotropic index at 23° C. in a range from 1.4         to 2.0, and     -   wherein the synthetic resin has a 100% modulus of 5 kgf/cm² or         greater.

Preferably, the synthetic resin is at least one selected from acrylic resins, urethane resins, and silicone resins.

Preferably, the stretchable coated fabric has an initial water-repellency (JIS L1092) of a fourth grade or higher, and a water repellency after 20 washings of a third grade or higher.

Preferably, the stretchable coated fabric has a hydraulic resistance (JIS L1092 A Method) in a range from 100 to 3000 mmH₂O and a moisture permeability of 3000 g/m²/24 hr or greater (JIS L1092 A-1 Method).

Preferably, the stretchable coated fabric has an air permeability of 6 cc/cm²/sec or less (JIS L1018 Frazier Method).

Preferably, the stretchable fiber fabric is a fabric knitted by a fine gauge knitting machine with 28 gauge or higher.

Preferably, the stretchable fiber fabric is a fabric that primarily comprises polyamide fibers and/or polyester fibers having a total fineness of 84 dtex or less, and that has a basis weight of 200 g/m² or less, a warp elongation (JIS L1096 A Method) at a load of 0.5 kgf of 45% or less, and a warp elongation at a load of 2.0 kgf of 75% or less.

In order to achieve the objective described above, a process for producing a stretchable coated fabric according to a second aspect of the present disclosure comprises

-   -   a step of preparing a stretchable fiber fabric treated for water         repellency with a fluorinated water repellent that comprises a         copolymer comprises a perfluoroalkyl group with six or less         carbon atoms, and     -   a step of applying a solution of a synthetic resin in a solvent         to at least one side of the stretchable fiber fabric,     -   wherein the fluorinated water repellent is used to impart a         toluene repellency of 100 seconds or longer to the stretchable         fabric, and the synthetic resin solution has a thixotropic index         at 23° C. in a range from 1.4 to 2.0, and     -   wherein the synthetic resin has a 100% modulus of 5 kgf/cm² or         greater.

Preferably, the synthetic resin is at least one selected from acrylic resins, urethane resins, and silicone resins.

Preferably, the stretchable fiber fabric is a fabric knitted by a fine gauge knitting machine with 28 gauge or higher.

Preferably, the stretchable fiber fabric is a fabric that primarily comprises polyamide fibers and/or polyester fibers having a total fineness of 84 dtex or less and that has a basis weight of 200 g/m² or less, a warp elongation (JIS L1096 A Method) at a load of 0.5 kgf of 45% or less, and a warp elongation at a load of 2.0 kgf of 75% or less.

Advantageous Effects of Invention

The stretchable coated fabric according to the present disclosure is treated for water repellency with a fluorinated water repellent that comprises a copolymer comprises-a perfluoroalkyl group with six or less carbon atoms (C6 fluorinated water repellent). The use of no C8 fluorinated water repellents that contain perfluorooctanoic acid, perfluorooctane sulfonate, and the like makes the fabric environmentally friendly. And the stretchable fiber fabric treated for water repellency with a C6 fluorinated water repellent has a toluene repellency of 100 seconds or longer; the synthetic resin solution applied to at least one side of the stretchable fiber fabric has a thixotropic index at 23° C. in a range from 1.4 to 2.0; and the synthetic resin has a 100% modulus of 5 kgf/cm² or greater. This prevents the synthetic resin from leaking to the back side, and allows formation of a resin coating film that has good film forming properties. Consequently, a stretchable coated fabric that has excellent moisture permeability, excellent waterproofness, and excellent windproof property can be provided.

DESCRIPTION OF EMBODIMENTS

The stretchable coated fabric according to an embodiment of the present disclosure will be described in detail below. The stretchable coated fabric according to the embodiment is produced by treating a stretchable fiber fabric for water repellency with a C6 fluorinated water repellent and then applying a synthetic resin to at least one side of the stretchable fiber fabric.

(1) Stretchable Fiber Fabric

The stretchable fiber fabric used in the embodiment includes, for example, woven fabrics, knitted fabrics, nonwoven fabrics, and the like. Among them, knitted fabrics are preferred in terms of stretchability. Fiber materials include, for example, natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as rayon and cupra, semisynthetic fibers such as acetate and triacetate, and synthetic fibers such as polyamides (nylon 6, nylon 66, and the like), polyesters (polyethylene terephthalate, polytrimethylene terephthalate, and the like), polyurethanes, and polyacrylics. Two or more of these materials may be used in combination. Among them, synthetic fibers are preferred in terms of fiber physical properties, and especially, a fabric that comprises polyamide fibers and/or polyester fibers is preferred. It is preferred to combine these fibers with stretchable fibers such as polyurethane fibers to produce, for example, a woven fabric, because it allows for control of stretchability. Moreover, among the polyester fibers, cationic-dyeable polyester fibers are preferred to prevent migration and sublimation of dispersed dye.

Preferably, the yarns that constitute the stretchable fiber fabric have a total fineness of 84 dtex (decitex) or less. If the yarns used in the embodiment have a total fineness of greater than 84 dtex, the yarns produce a hard hand feeling. In addition, if the stretchable fiber fabric is, for example, a knitted fabric, such yarns produce large irregularities in the surface of the stretchable fiber fabric. Thus, the film-forming properties are reduced. As a result, the fabric may not provide physical properties such as hydraulic resistance and air permeability that are required after coating.

Preferably, the stretchable fiber fabric has a basis weight of 200 g/m² or less. If the stretchable fiber fabric has a basis weight of greater than 200 g/m², such fabric provides a heavy garment. And the resulting garment tends to have a hard hand feeling.

Preferably, the stretchable fiber fabric has a warp elongation (JIS L1096 A Method) at a load of 0.5 kgf of 45% or less. Moreover, the stretchable fiber fabric preferably has a warp elongation at a load of 2.0 kgf of 75% or less. If the fabric has a warp elongation at a load of 0.5 kgf of more than 45% and a warp elongation at a load of 2.0 kgf of more than 75%, the fabric is excessively stretched in the warp direction. This results in a larger reduction in width in the weft direction, and thus the fabric may not provide physical properties such as hydraulic resistance and air permeability that are required after coating.

Preferably, the stretchable fiber fabric used in the embodiment is a fabric knitted by a fine gauge knitting machine with 28 gauge or higher. If the knitting machine has less than 28-gauge needles, the stretchable fiber fabric has a lower knit density, thereby reducing the film forming properties in coating the fabric. Thus, the fabric may not provide the necessary physical properties such as moisture permeability, hydraulic resistance and air permeability.

The stretchable fiber fabric may be dyed, where necessary. The stretchable fiber fabric may be, for example, treated for antistatic protection, treated for flame retardancy, and calendered.

(2) C6 Fluorinated Water Repellent

In the embodiment, the fabric is treated for water repellency before application of the synthetic resin. The water-repellent treatment not only improves waterproofness, but also inhibits the synthetic resin solution from deeply penetrating the fiber fabric. This allows prevention of a hard hand feeling of the stretchable fiber fabric and improvement in physical properties such as hydraulic resistance and air permeability.

A water repellent used in the embodiment is a fluorinated water repellent that comprises a copolymer comprises a perfluoroalkyl group with six or less carbon atoms (C6 fluorinated water repellent), because such repellent can impart high water repellency and is environmentally and biologically friendly. In the embodiment, the C6 fluorinated water repellent is preferably contained in an amount of 80-100% based on the overall water repellents used, and a paraffin-based water repellent and/or a silicone-based water repellent as another water-repellent may be contained in an amount of less than 20%.

Preferably, the water repellent used in the embodiment impart a toluene repellency of 100 seconds or longer to a fabric treated for water repellency when the repellent is combined with the stretchable fiber fabric used, as determined by a measurement method described below. If the fabric has a toluene repellency of less than 100 seconds, the resin more easily penetrates the stretchable fiber fabric. Thus, the resin leaks through the coated surface to the other side, and thus the fabric may not provide the necessary physical properties such as hydraulic resistance and air permeability.

The C6 fluorinated water repellent used in the present disclosure may be individually used, or two or more thereof may be used in combination, as long as performance requirements such as water repellency and oil-repellency are met depending on usage.

(3) Coating Resin

The synthetic resin solution used in the embodiment should have a thixotropic index at 23° C. in a range from 1.4 to 2.0. More preferably, the thixotropic index is in a range from 1.45 to 1.7. The term thixotropic index refers to a viscosity at a low rotation speed divided by a viscosity at a high rotation speed, as determined with a rotary viscometer at constant temperature. If the thixotropic index is less than 1.4, the synthetic resin that has been coated onto the fiber fabric to a desired thickness is flowable until the resin cures, and thus the fabric is unable to retain the coating film. If the thixotropic index is more than 2.0, the viscosity significantly changes relative to shear stress during coating, and thus there is difficulty in controlling the coating form.

During coating, the synthetic resin solution preferably has a viscosity at 23° C. in a range from 8000 to 25000 mPa·s, and more preferably in a range from 10000 to 20000 mPa·s. If the viscosity at 23° C. is less than 8000 mPa·s, the synthetic resin may deeply penetrate the fiber fabric and produce a hard hand feeling. And the synthetic resin solution may leak through the fiber fabric to the other side. On the other hand, if the viscosity at 23° C. is more than 25000 mPa·s, streaks and air bubbles are prone to be formed during coating. As a result, it becomes difficult to form a resin film, and thus sufficient hydraulic resistance and sufficient windproof property may not be provided.

Preferably, the synthetic resin used in the present disclosure has a 100% modulus of 5 kgf/cm² or greater. If the synthetic resin used has a 100% modulus of less than 5 kgf/cm², it becomes difficult to form a continuous film during coating. The film may also have a reduced strength, and the necessary physical properties such as hydraulic resistance and air permeability may not be achieved. When considering use in a garment, the upper limit for the 100% modulus is preferably less than 60 kgf/cm² in order not to impair the hand feeling.

The synthetic resin used in the present disclosure can be at least one selected from acrylic resins, urethane resins, and silicone resins. Particularly, the acrylic resins and the urethane resins can be preferably used, because these resins can provide the necessary film strength.

These synthetic resins alone may not be able to provide the necessary moisture permeability and the necessary air permeability. In this case, a pigment for coloration can be added into these synthetic resins, to the extent that the pigment does not impair the physical properties. To improve the moisture permeability and the hand feeling of the surface, inorganic/organic particulates can be added. A crosslinking agent, an antibacterial agent, and/or the like can be added to improve the film strength.

For example, to improve the moisture permeability and the air permeability, the synthetic resin is used in an amount of 70% by weight or more, and 30% by weight or less of inorganic particulates having an average particle size from 0.2 to 20 μm and an appropriate amount of water are admixed into the synthetic resin. This allows achievement of the necessary moisture permeability and the necessary air permeability. If a coating resin contains the synthetic resin in an amount of less than 70% by weight and inorganic particulates having an average particle size from 0.2 μm to 20 μm in an amount of more than 30% by weight, the resulting synthetic resin film has a reduced strength, which is not preferred. If the inorganic particulates added have an average particle size from 0.2 μm to 20 μm, the necessary hydraulic resistance, the necessary moisture permeability, and the necessary air permeability can be controlled, and the synthetic resin film does not have a significantly reduced strength. If the inorganic particulates added have an average particle size of more than 20 μm, the film strength is reduced, which is not preferred. If the inorganic particulates added have an average particle size of less than 0.2 μm, the necessary hydraulic resistance, the necessary moisture permeability, and the necessary air permeability may not be able to be controlled.

(4) Coating Pretreatment (Water-Repellent Treatment)

The stretchable fiber fabric used in the embodiment is previously scoured and dyed according to routine procedures, and then treated, as normally, for water repellency with a C6 fluorinated water repellent as a pretreatment prior to coating. As the treatment process, a padding process, a coating process, a gravure coating process, a spraying process, or the like can be employed.

The C6 fluorinated water repellent alone may not impart wash resistance to the water repellency, and thus it is preferred to add a melamine or isocyanate crosslinking agent, a crosslinking catalyst, and/or the like, when the fabric is treated for water repellency. Moreover, an antistatic agent, a sewability enhancer, and/or the like also may be added, where necessary. Before or after the treatment for water repellency, the fabric may also be calendered, where necessary.

If it is additionally desired to improve the tear strength, the hand feeling, the smoothness, and/or the like of the coated fabric, a mixed aqueous dispersion of an emulsion of a fluorinated water repellent and an emulsion of polyethylen may be used as a water repellent. In addition to the dispersion, use of a silicone resin, a lubricant, and/or the like, for example, can further improve the hand feeling, the smoothness, and the like.

(5) Coating Process

Preferably, a process for coating at least one side of the stretchable fiber fabric with the synthetic resin in the embodiment is a common knife coating process. A known coating device such as a floating knife coater or a knife over roll coater can be used to coat at least one side of the stretchable fiber fabric with the synthetic resin. After coating, the fabric is preferably dried in a common hot air dryer at a temperature from 100 to 120° C. for 1 to 5 minutes.

In the embodiment, the coating resin is preferably applied in an amount so that the resin solids present in an amount from 12 to 25 g/m². If the resin solids present in an amount of less than 12 g/m², the fabric is less likely to provide the necessary physical properties such as hydraulic resistance and air permeability. On the other hand, if the resin solids present in an amount of more than 25 g/m², the fabric tends to have a hard hand feeling.

(6) Stretchable Coated Fabric

Preferably, the stretchable coated fabric in the embodiment has an initial water-repellency (JIS L1092) of a fourth grade or higher and a water repellency after 20 washings of a third grade or higher. And the stretchable coated fabric preferably has a hydraulic resistance (JIS L1092 A Method) in a range from 100 to 3000 mmH₂O. Particularly, the stretchable coated fabric for outdoor and sports applications preferably has a hydraulic resistance of 300 mmH₂O or higher.

Preferably, the stretchable coated fabric in the embodiment has a moisture permeability (JIS L1092 A-1 Method) of 3000 g/m²/24 hr or greater. If the stretchable coated fabric has a moisture permeability of less than 3000 g/m²/24 hr, the fabric becomes stuffy when worn as a garment, which may bring about a discomfort.

Preferably, the stretchable coated fabric in the embodiment has an air permeability of 6 cc/cm²/sec or less (JIS L1018 Frazier Method). Typically, if the air permeability is 20 cc/cm²/sec or less, the fabric can be used as a common windproof material. However, when a stretchable coated fabric is stretched in the warp or weft direction, the fabric tends to exhibit a rapid increase in air permeability. Thus, a stretchable coated fabric is required to have a smaller air permeability. And recently, some applications have required a smaller air permeability. For example, knitted materials are increasingly used for down garments, and a stretchable coated fabric in such application preferably has an air permeability from 1 to 3 cc/cm²/sec or less. When a stretchable coated fabric is used for sport applications and/or the like, the stretchable coated fabric having an air permeability of more than 6 cc/cm²/sec cannot provide sufficient windproofness, when worn as a sports garment.

When the stretchable coated fabric with only one side coated in the embodiment is used as a garment, the uncoated side or the coated side may be used as the outer surface. Typically, the uncoated side is used as the outer surface for water repellency, although the coated side may be used as the outer surface. In the latter case, however, the water repellency is reduced due to the coating resin film, which is not preferred.

EXAMPLES

Now, the present disclosure will be described more specifically with reference to Examples, although the present disclosure is not limited in any way to Examples described below.

As described below, stretchable coated fabrics according to Examples 1-5 of the present disclosure were produced to evaluate their performance. And for comparison, stretchable coated fabrics of Comparative Examples 1-4 were produced to evaluate their performance.

In Examples and Comparative Examples, measurement of various physical property values and evaluation of the performance of the stretchable coated fabrics were done as follows.

(1) Thixotropic Index

The thixotropic index of the synthetic resin solutions is a ratio of a viscosity at a rotation speed of 6 rpm to a viscosity at a rotation speed of 30 rpm, as determined at 23° C. with a Brookfield-type (BM-type) viscometer from Toki Sangyo Co., Ltd. with a No. 4 spindle (without guard), and is represented by a general formula (A):

Thixotropic Index=Viscosity(6 rpm)/Viscosity(30 rpm)  (A)

(2) Viscosity of Synthetic Resin Solution

The viscosity of the synthetic resin solutions is a viscosity at a rotation speed 12 rpm at 23° C., as determined with a Brookfield-type (BM-type) viscometer from Toki Sangyo Co., Ltd. with a No. 4 spindle (without guard).

(3) 100% Modulus of Synthetic Resin

The term modulus refers to the stress required to stretch a test specimen to a given elongation, and was measured as described below. A crosslinking agent for the coating resin composition was added to a synthetic resin to be measured, and then a diluting solvent for the coating resin composition was added to dilute the synthetic resin solution so that the resin solution had a viscosity from 3000 to 5000 mPa·s at room temperature. The synthetic resin solution was injected into a mold to form a resin film having a thickness of about 0.2 mm, and then dried at ambient temperature. After drying, the film was treated with heat at 150° C. for 3 minutes to cure the film. In this way, a sheet of the synthetic resin was prepared and cut with a dumbbell-shaped die to produce a No. 2 tensile test specimen according to JIS. Then, the sheet thickness of the synthetic resin was measured. A 1 cm bench mark was drawn on the section having a dumbbell width of 1 cm. At a temperature of 23° C., the specimen was stretched at a rate of 200 mm/min until the longitudinal length of the mark was 2 cm to measure the 100% modulus.

(4) Method for Evaluating Toluene Repellency

Toluene as an organic solvent was added dropwise via syringe onto a stretchable fiber fabric treated for water repellency to form a droplet having a diameter of 5 mm, and then the time for the toluene to completely penetrate the fabric was measured.

(5) Warp Elongation of Fiber Fabric (JIS L1096 A Method)

Measurement was made with a specimen having a width of 5 cm, a grip distance of 20 cm, a tensile speed of 200 mm/min, and a load of 0.5 kgf and 2.0 kgf.

(6) Water Repellency

Measurement was made according to the spraying method of JIS L1092.

(7) Hydraulic Resistance

Measurement was made according to the low water-pressure method of JIS L1092 A.

(8) Moisture Permeability

Measurement was made according to JIS L1092 A-1 Method (calcium chloride method).

(9) Air Permeability

Measurement was made according to the Frazier method of JIS L1018.

(10) Hand Feeling

The hand feeling of a specimen was evaluated according to the following criteria.

-   -   Very good: Very soft     -   Good: Soft     -   Slightly bad: Slightly hard     -   Bad: Hard

(11) Quality of Coated Surface

The quality of the coated surface was evaluated by observing the resin film covering the coated surface according to the following criteria.

Good: The coating resin does not significantly penetrate the fabric, and the resin film covers the coated surface of the fabric.

Not bad: The coating resin slightly penetrates the fabric, although the resin film almost covers the coated surface of the fabric.

Bad: The coating resin mostly penetrates the fabric, and little resin film is formed on the coated surface.

Example 1

A 33 dtex/36 filament polyester yarn was used to knit an interlock knitted fabric by a 40 gauge flat knitting machine. Then, the fabric was scoured and dyed according to routine procedures. The knitted fabric dyed had a basis weight of 74 g/m². The knitted fabric had a warp elongation at a load of 0.5 kgf of 8.6% and a warp elongation at a load of 2.0 kgf of 24.9%.

Next, the knitted fabric produced above was immersed in an aqueous solution containing two types of C6 fluorinated water repellents as described in Composition 1. The fabric was wrung out by a mangle (to a wet pick-up of 55% by weight), dried at 120° C. for 60 seconds, and then treated with heat at 160° C. for 60 seconds for water repellency. After the water-repellent treatment, the toluene repellency of the water-repellent fabric was measured to be 153 seconds.

<Composition 1>

1) NUVA 2114 LIQ 3.0% by weight (C6 fluorinated water repellent from Clariant (Japan) Co., Ltd.) 2) ARKOPHOB NANO 2605 LIQ 3.0% by weight (C6 fluorinated water repellent from Clariant (Japan) Co., Ltd.) 3) NICEPOLE FE-26 0.5% by weight (Antistatic agent from Nicca Chemical Co., Ltd.) 4) MEIKANATE TP 10 0.5% by weight (Isocyanate crosslinking agent from Meisei Chemical Works, Ltd.) 5) Isopropyl alcohol 3.0% by weight (Penetration enhancer) 6) Water 90.0% by weight

Next, a synthetic resin solution as described in Composition 2 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Example 1. The stretchable coated fabric had a basis weight of 90 g/m².

<Composition 2>

1) XE-5573 100.0 parts by weight (Acrylic resin solution (having a 100% modulus of 9 kgf/cm²) from Tohpe Corp.) 2) RESAMINE UD crosslinking agent 2.0 parts by weight (Urethane crosslinking agent from Dainichiseika Color & Chemicals Mfg. Co., Ltd.) 3) Toluene 17.0 parts by weight (Diluting solvent)

The synthetic resin solution had a viscosity of 15900 mPa·s (as determined with a Brookfield-type (BM-type) viscometer) and a thixotropic index at 23° C. of 1.44.

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 1 cc/cm²/sec, a hydraulic resistance of 300 mmH₂O, a moisture permeability of 6568 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric.

Example 2

A 22 dtex/24 filament polyester yarn was used to knit an interlock knitted fabric by a 40 gauge flat knitting machine. Then, the fabric was scoured and dyed according to routine procedures. The knitted fabric dyed had a basis weight of 55 g/m². The knitted fabric had a warp elongation at a load of 0.5 kgf of 9.6% and a warp elongation at a load of 2.0 kgf of 23.0%.

Next, the knitted fabric produced above was immersed in an aqueous solution containing two types of C6 fluorinated water repellents as described above in Composition 1. The fabric was wrung out by a mangle (to a wet pick-up of 53% by weight), dried at 120° C. for 60 seconds, and then treated with heat at 160° C. for 60 seconds for water repellency. After the water-repellent treatment, the toluene repellency of the water-repellent fabric was measured to be 144 seconds.

Next, the synthetic resin solution as described above in Composition 2 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Example 2. The stretchable coated fabric had a basis weight of 71 g/m².

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 1 cc/cm²/sec, a hydraulic resistance of 220 mmH₂O, a water-vapor permeability of 8384 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric.

Example 3

A 56 dtex/48 filament 6 nylon yarn was used to knit a 32 gauge tricot knitted fabric. Then, the fabric was scoured and dyed according to routine procedures. The knitted fabric dyed had a basis weight of 178 g/m². The knitted fabric had a warp elongation at a load of 0.5 kgf of 8.2% and a warp elongation at a load of 2.0 kgf of 19.3%.

Next, the knitted fabric produced above was immersed in an aqueous solution containing two types of C6 fluorinated water repellents having different performance characteristics as described above in Composition 1. The fabric was wrung out by a mangle (to a wet pick-up of 56% by weight), dried at 120° C. for 60 seconds, and then treated with heat at 160° C. for 60 seconds for water repellency. After the water-repellent treatment, the toluene repellency of the water-repellent fabric was measured to be 174 seconds.

Next, the synthetic resin solution as described above in Composition 2 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Example 3. The stretchable coated fabric had a basis weight of 194 g/m².

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 3 cc/cm²/sec, a hydraulic resistance of 180 mmH₂O, a moisture permeability of 7240 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric.

Example 4

An 84 dtex/72 filament polyester yarn was used to knit an interlock knitted fabric by a 28 gauge flat knitting machine. Then, the fabric was scoured and dyed according to routine procedures. The knitted fabric dyed had a basis weight of 188 g/m². The knitted fabric had a warp elongation at a load of 0.5 kgf of 5.3% and a warp elongation at a load of 2.0 kgf of 10.5%.

Next, the knitted fabric produced above was immersed in an aqueous solution containing two types of C6 fluorinated water repellents having different performance characteristics as described above in Composition 1. The fabric was wrung out by a mangle (to a wet pick-up of 54% by weight), dried at 120° C. for 60 seconds, and then treated with heat at 160° C. for 60 seconds for water repellency. After the water-repellent treatment, the toluene repellency of the water-repellent fabric was measured to be 163 seconds.

Next, the synthetic resin solution as described above in Composition 2 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Example 4. The stretchable coated fabric had a basis weight of 204 g/m².

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 1 cc/cm²/sec, a hydraulic resistance of 220 mmH₂O, a moisture permeability of 8453 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric.

Example 5

To a water-repellent knitted fabric as used in Example 1, a synthetic resin solution as described in Composition 3 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 19 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Example 5. The stretchable coated fabric had a basis weight of 93 g/m².

<Composition 3>

1) XE-5573 100.0 parts by weight (Acrylic resin solution (having a 100% modulus of 9 kgf/cm²) from Tohpe Corp.) 2) RESAMINE UD crosslinking agent 2.0 parts by weight (Urethane crosslinking agent from Dainichiseika Color & Chemicals Mfg. Co., Ltd.) 3) Toluene 6.0 parts by weight (Diluting solvent)

The synthetic resin solution had a viscosity of 24800 mPa·s (as determined with a Brookfield-type (BM-type) viscometer) and a thixotropic index at 23° C. of 1.69.

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 0.5 cc/cm²/sec, a hydraulic resistance of 360 mmH₂O, a moisture permeability of 6165 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. The stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric.

Comparative Example 1

To a water-repellent knitted fabric as used in Example 1, a synthetic resin solution as described in Composition 4 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 18 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Comparative Example 1. The stretchable coated fabric had a basis weight of 92 g/m².

<Composition 4>

1) SA-6218 100.0 parts by weight (Acrylic resin solution (having a 100% modulus of 4 kgf/cm²) from Tohpe Corp.) 2) RESAMINE UD crosslinking agent 2.0 parts by weight (Urethane crosslinking agent from Dainichiseika Color & Chemicals Mfg. Co., Ltd.) 3) Toluene 8.0 parts by weight (Diluting solvent)

The synthetic resin solution had a viscosity of 15500 mPa·s (as determined with a Brookfield-type (BM-type) viscometer) and a thixotropic index at 23° C. of 1.32.

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 12 cc/cm²/sec, a hydraulic resistance of 90 mmH₂O, a moisture permeability of 8965 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a slightly hard hand feel. When the quality of the coated surface was observed, the coating resin slightly penetrated the fabric, although the resin film almost covered the coated surface of the fabric.

Comparative Example 2

A water-repellent fabric as used in Comparative Example 1 was treated for water repellency with a C8 fluorinated water repellent as described below in Composition 5. Then, the synthetic resin solution as described in Composition 4 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Comparative Example 2. When the toluene repellency of the water-repellent fabric was measured prior to the coating, the toluene did not penetrate the fabric for 600 seconds or longer. The stretchable coated fabric had a basis weight of 90 g/m².

<Composition 5>

1) AG-7000 6.0% by weight (C8 fluorinated water repellent from Asahi Glass Co., Ltd.) 2) NICEPOLE FE-26 0.5% by weight (Antistatic agent from Nicca Chemical Co., Ltd.) 3) MEIKANATE TP 10 0.5% by weight (Isocyanate crosslinking agent from Meisei Chemical Works, Ltd.) 4) Isopropyl alcohol 3.0% by weight (Penetration enhancer) 5) Water 90.0% by weight

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 0.5 cc/cm²/sec, a hydraulic resistance of 300 mmH₂O, a moisture permeability of 6350 g/m²/24 hr, an initial water repellency of a fourth-to-fifth grade, and a water repellency after 20 washings of a fourth grade. And the stretchable coated fabric had a soft hand feel. When the quality of the coated surface was observed, the coating resin did not significantly penetrate the fabric, and the resin film covered the coated surface of the fabric. According to the above, the fabric treated with the C8 fluorinated water repellent had good physical properties.

Comparative Example 3

To a water-repellent knitted fabric as used in Example 1, a synthetic resin solution as described in Composition 6 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 16 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Comparative Example 3. The stretchable coated fabric had a basis weight of 90 g/m².

<Composition 6>

1) SA-6218 100.0 parts by weight (Acrylic resin solution (having a 100% modulus of 4 kgf/cm²) from Tohpe Corp.) 2) RESAMINE UD crosslinking agent 2.0 parts by weight (Urethane crosslinking agent from Dainichiseika Color & Chemicals Mfg. Co., Ltd.) 3) Toluene 2.0 parts by weight (Diluting solvent)

The synthetic resin solution had a viscosity of 19400 mPa·s (as determined with a Brookfield-type (BM-type) viscometer) and a thixotropic index at 23° C. of 1.42.

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 8 cc/cm²/sec, a hydraulic resistance of 140 mmH₂O, a moisture permeability of 7920 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. And the stretchable coated fabric had a slightly hard hand feel. When the quality of the coated surface was observed, the coating resin slightly penetrated the fabric, although the resin film almost covered the coated surface of the fabric.

Comparative Example 4

A knitted fabric as used in Example 2 was immersed in an aqueous solution containing a single type of a C6 fluorinated water repellent as described in Composition 7. The fabric was wrung out by a mangle (to a wet pick-up of 53% by weight), dried at 120° C. for 60 seconds, and then treated with heat at 160° C. for 60 seconds for water repellency. After the water-repellent treatment, the toluene repellency of the water-repellent fabric was measured to be 36 seconds.

<Composition 7>

1) NUVA 2114 LIQ 6.0% by weight (C6 fluorinated water repellent from Clariant (Japan) K.K.) 2) NICEPOLE FE-26 0.5% by weight (Antistatic agent from Nicca Chemical Co., Ltd.) 3) MEIKANATE TP 10 0.5% by weight (Isocyanate crosslinking agent from Meisei Chemical Works, Ltd.) 4) Isopropyl alcohol 3.0% by weight (Penetration enhancer) 5) Water 90.0% by weight

Next, the synthetic resin solution as described above in Composition 2 was applied by a floating knife coating process using a knife coater. The solution was applied to the knitted fabric in an amount so that the resin solids present in an amount of 17 g/m², and then treated with heat at 120° C. for a minute. Then, the fabric was heat-set at 150° C. to give a stretchable coated fabric of Comparative Example 4. The stretchable coated fabric had a basis weight of 72 g/m².

When the resulting stretchable coated fabric was measured for physical properties and the like, the fabric had an air permeability of 10 cc/cm²/sec, a hydraulic resistance of 80 mmH₂O, a moisture permeability of 7453 g/m²/24 hr, an initial water repellency of a fourth grade, and a water repellency after 20 washings of a third grade. The stretchable coated fabric had a hard hand feel. When the quality of the coated surface was observed, the coating resin slightly penetrated the fabric, although the resin film almost covered the coated surface of the fabric.

The results of Examples 1-5 described above are summarized in Table 1. The results of Comparative Examples 1-4 are summarized in Table 2.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Fabric Fiber 33 dtex 22 dtex 56 dtex 84 dtex 33 dtex polyester polyester nylon polyester polyester Knit Gauge 40 40 32 28 40 Fabric Basis Weight 74 55 178 188 74 Water Repellent C6 Water C6 Water C6 Water C6 Water C6 Water Repellent Repellent Repellent Repellent Repellent Toluene Repellency (Sec) 153 144 174 163 153 Warp 0.5 kg 8.6 9.6 8.2 5.3 8.6 Elongation 2.0 kg 24.9 23.0 19.3 10.5 24.9 (%) Resin Type Acrylic Acrylic Acrylic Acrylic Acrylic 100% Modulus 9 9 9 9 9 Thixotropic Index of 1.44 1.44 1.44 1.44 1.69 Coating Resin Air Permeability 1 1 3 1 0.5 Hydraulic Resistance 300 220 180 220 360 Moisture Permeability 6568 8384 7240 8453 6165 Water Initial 4th grade 4th grade 4th grade 4th grade 4th grade Repellency After 20 3rd grade 3rd grade 3rd grade 3rd grade 3rd grade Washings Hand Feeling Good Good Good Good Good Quality of Coated Surface Good Good Good Good Good

TABLE 2 Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Fabric Fiber 33 dtex 33 dtex 33 dtex 22 dtex polyester polyester polyester polyester Knit Gauge 40 40 40 40 Fabric Basis Weight 74 74 74 55 Water Repellent C6 Water C8 Water C6 Water C6 Water Repellent Repellent Repellent Repellent Toluene Repellency (Sec) 153 600 or longer 153 36 Warp Elongation (%) 8.6 8.6 8.6 8.6 9.6 24.9 24.9 24.9 24.9 23.0 Resin Type Acrylic Acrylic Acrylic Acrylic 100% Modulus 4 4 4 9 Thixotropic Index of Coating Resin 1.32 1.32 1.42 1.44 Air Permeability 12 0.5 8 10 Hydraulic Resistance 90 300 140 80 Moisture Permeability 8965 6350 7920 7453 Water Initial 4th grade 4th-5th grade 4th grade 4th grade Repellency After 20 3rd grade 4th grade 3rd grade 3rd grade Washings Hand Feeling Slightly bad Good Slightly bad Slightly bad Quality of Coated Surface Not bad Good Not bad Not bad

As shown in Table 1, all of the stretchable coated fabrics according to Examples 1-5 met the requirements that a fluorinated water repellent should have a toluene repellency of 100 seconds or longer and that a synthetic resin (coating resin) should have an thixotropic index at 23° C. in a range from 1.4 to 2.0 and a 100% modulus of 5 kgr/cm² or greater. Consequently, the fabrics had a small air permeability of 3 cc/cm²/sec or less and thus had sufficient windproof property. The fabrics also had a high hydraulic resistance of 180 mmH₂O or higher and a high_(—) moisture permeability of 6165 g/m²/24 hr or greater, and thus had sufficient moisture permeability and waterproofness.

And the fabrics had an initial water repellency of a fourth grade and a water repellency after 20 washings of a third grade, which were sufficient. The fabrics also had a soft hand feeling and a good quality of the coated surface, as their resin film almost covered the coated surface of the fabric.

In contrast, as shown in Table 2, the synthetic resin (coating resin) of the stretchable coated fabric of Comparative Example 1 had a thixotropic index at 23° C. of 1.32, which did not meet the requirement in a range from 1.4 to 2.0, a 100% modulus of 4 kgf/cm², which did not meet the requirement of 5 kgf/cm² or greater. Consequently, the fabric had a large air permeability of 12 cc/cm²/sec and thus had insufficient windproof property. The fabric also had a low hydraulic resistance of 90 mmH₂O, and thus the waterproofness was problematic. And the fabric had a hard hand feeling, and the quality of the coated surface was problematic.

As shown in Table 2, the stretchable coated fabric of Comparative Example 2 had no problem with the air permeability, the hydraulic resistance, the moisture permeability, the hand feeling, and the quality of the coated surface, although the fabric did not solve the environmentally sensitive problem, as the fabric uses a C8 fluorinated water repellent instead of a C6 fluorinated water repellent.

As shown in Table 2, the synthetic resin (coating resin) of the stretchable coated fabric of Comparative Example 3 had a thixotropic index at 23° C. of 1.42, which met the requirement in a range from 1.4 to 2.0, and a 100% modulus of 4 kgf/cm², which did not meet the requirement of 5 kgf/cm² or greater. Consequently, the fabric had a high air permeability of 8 cc/cm²/sec and thus had insufficient windproof property. The fabric also had a slightly insufficient hydraulic resistance of 140 mmH₂O or higher. And the fabric also had a problem with the hand feel and the quality of the coated surface.

As shown in Table 2, the synthetic resin (coating resin) of the stretchable coated fabric of Comparative Example 4 had a thixotropic index at 23° C. of 1.44, which met the requirement in a range from 1.4 to 2.0, and a 100% modulus of 9 kgf/cm², which met the requirement of 5 kgf/cm² or greater. However, the fluorinated water repellent had a small toluene repellency of 36 seconds, which did not meet the requirement of 100 seconds or longer. Consequently, the fabric had a large air permeability of 10 cc/cm²/sec and thus had insufficient windproof property. The fabric also had an insufficient hydraulic resistance of 80 mmH₂O or higher. And the fabric had a problem with the hand feel and the quality of the coated surface.

As shown in Table 1, the synthetic resin (coating resin) of the stretchable coated fabric of Example 5 had a thixotropic index at 23° C. of 1.69, which was larger than the thixotropic index of 1.44 of the stretchable coated fabrics of Examples 1-4. Thus, the fabric had a smaller air permeability of 0.5 cc/cm²/sec and thus had particularly good_windproof property. The fabric also had a larger hydraulic resistance of 360 mmH₂O and thus had good waterproofness.

As described above, the stretchable coated fabrics according to the embodiment and Examples have good water-vapor permeability, good waterproofness, and good windproofness. Thus, the fabrics are favorably used for outdoor and sports applications in the garment field.

Various embodiments and modifications can be made without departing from the broad spirit and scope of the present disclosure. The embodiment and Examples described above are presented for illustration of the present disclosure and do not limit the scope of the present disclosure.

The present application is based on Japanese Patent Application No. 2012-132309 filed on Jun. 11, 2012. This application claims the benefit of Japanese Patent Application No. 2012-132309, filed on Jun. 11, 2012, the entire disclosure of which is incorporated by reference herein.

INDUSTRIAL APPLICABILITY

The stretchable coated fabric according to the present disclosure is suitable for a garment fabric used for outdoor and sports applications. 

1. A stretchable coated fabric produced by treating a stretchable fiber fabric for water repellency with a fluorinated water repellent that comprises a copolymer comprising a perfluoroalkyl group with six or less carbon atoms and applying a synthetic resin solution to at least one side of the stretchable fiber fabric to form a resin coating film that comprises a synthetic resin, wherein the stretchable fiber fabric treated for water repellency with the fluorinated water repellent has a toluene repellency of 100 seconds or longer, and the synthetic resin solution has a thixotropic index at 23° C. in a range from 1.4 to 2.0, and wherein the synthetic resin has a 100% modulus of 5 kgf/cm² or greater.
 2. The stretchable coated fabric according to claim 1, wherein the synthetic resin is at least one selected from acrylic resins, urethane resins, and silicone resins.
 3. The stretchable coated fabric according to claim 1, wherein the stretchable coated fabric has an initial water-repellency (JIS L1092) of a fourth grade or higher and a water repellency after 20 washings of a third grade or higher.
 4. The stretchable coated fabric according to claim 3, wherein the stretchable coated fabric has a hydraulic resistance (JIS L1092 A Method) in a range from 100 to 3000 mmH₂O and a moisture permeability of 3000 g/m²/24 hr or greater (JIS L1092 A-1 Method).
 5. The stretchable coated fabric according to claim 4, wherein the stretchable coated fabric has an air permeability of 6 cc/cm²/sec or less (JIS L1018 Frazier Method).
 6. The stretchable coated fabric according to claim 1, wherein the stretchable fiber fabric is a fabric knitted by a fine gauge knitting machine with 28 gauge or higher.
 7. The stretchable coated fabric according to claim 1, wherein the stretchable fiber fabric is a fabric that primarily comprises polyamide fibers and/or polyester fibers having a total fineness of 84 dtex or less, and that has a basis weight of 200 g/m² or less, a warp elongation (JIS L1096 A Method) at a load of 0.5 kgf of 45% or less, and a warp elongation at a load of 2.0 kgf of 75% or less.
 8. A process for producing a stretchable coated fabric, the process comprising a step of preparing a stretchable fiber fabric treated for water repellency with a fluorinated water repellent that comprises a copolymer comprising a perfluoroalkyl group with six or less carbon atoms, and a step of applying a solution of a synthetic resin in a solvent to at least one side of the stretchable fiber fabric, wherein the fluorinated water repellent is used to impart a toluene repellency of 100 seconds or longer to the stretchable fabric, and the synthetic resin solution has a thixotropic index at 23° C. in a range from 1.4 to 2.0, and wherein the synthetic resin has a 100% modulus of 5 kgf/cm² or greater.
 9. The process for producing a stretchable coated fabric according to claim 8, wherein the synthetic resin is at least one selected from acrylic resins, urethane resins, and silicone resins.
 10. The process for producing a stretchable coated fabric according to claim 8, wherein the stretchable fiber fabric is a fabric knitted by a fine gauge knitting machine with 28 gauge or higher.
 11. The process for producing a stretchable coated fabric according to claim 8, wherein the stretchable fiber fabric is a fabric that primarily comprises polyamide fibers and/or polyester fibers having a total fineness of 84 dtex or less and that has a basis weight of 200 g/m² or less, a warp elongation (JIS L1096 A Method) at a load of 0.5 kgf of 45% or less, and a warp elongation at a load of 2.0 kgf of 75% or less. 